Patent GB-1034352-A (GB)
Title: Unsaturated aldehydes and their use in flavouring food
Inventor: DORP DAVID ADRIAN VAN
IPC: A23L27/20
Filed: 1962-08-23
Abstract: Hept-1-yne is prepared from sodium acetylide and amyl bromide  Deca 1,4-diyne is prepared by treatment of the Grignard derivative of hept-1-yne with propargyl bromide in the presence of cuprous chloride.  2 - Methyltetradeca - 5,8 - diyne - 2 - ene is prepared by treatment of the Grignard derivative of deca-1,4-diyne with 1-bromo-3-methylbutene-2 in the presence of cuprous cyanide.ALSO:The invention comprises undeca-2,5-dienal; dodeca - 3,6 - dienal; trideca - 4,7 - dienal; trideca - 2,4,7 - trienal; tetradeca - 2,4,8-trienal; tetradeca - 2,5,8 - trienal; pentadeca-3,6,9 - trienal; hexadeca - 4,7,10 - trienal; hexadeca - 2,4,7,10 - tetraenal; heptadeca-2,5,8,11-tetraenal. The aldehydes of the invention and other C11 to C17 aliphatic aldehydes containing 2 to 4 olefinic bonds may be prepared by oxidation of the corresponding alcohols, by hydrolysis of the corresponding acetals, hemiacetals and the esters of the hypothetical gem diols corresponding to the aldehydes, or by autoxidation of compounds, preferably carboxylic acids or functional derivatives thereof, containing the grouping C5H11-(CH = CH-CH2)nC wherein n is 3 or 4.  The oxidations may be effected in the presence of an oxidation catalyst, preferably chlorophyll.  The bisulphate addition compounds of said C11 to C17 aldehydes can be obtained by oxidation or autoxidation, in the presence or absence of a catalyst, of a precursor, followed by treatment with the bisulphite of an alkali metal or by addition of a solution of SO2 in water to or passage of gaseous SO2 through the reaction mixture during said oxidation.  In Example 1, hept-1-yne in the form of its Grignard derivative was treated with proparyl bromide in the presence of cuprous chloride to form deca-1,4-diyne, which as its Grignard derivative was reacted with orthoformic ester to give 1,1-diethoxyundeca-2,5-diyne, which was hydrogenated over Lindlar's catalyst to 1,1-diethoxyundeca-2,5-diene.  In Example 2, 2,3-dibromopropanol was reacted with orthoformic ester to give 1,1-diethoxy - 2,3 - dibromopropane, which on dehydrobromination with sodamide in liquid ammonia gives 1,1-diethoxyprop-2-yne, which as its Grignard is reacted with propargyl bromide in the presence of cuprous chloride to give 1,1-diethoxyhexa-2,5-diyne.  In Example 3, 1,1-diethoxyhexa-2,5-diyne as its Grignard derivative was reacted with oct-2-yne bromide in the presence of cuprous chloride to give 1,1-diethoxytetra-2,5,8-triyne, which was hydrogenated over a Lindlar's catalyst to give 1,1-diethoxytetra-2,5,8-triene.  In Example 4, 1,1-diethoxyhexa-2,5-diyne was treated with ethyl magnesium bromide to form the Grignard derivative, which was reacted with 1-bromo-undeca-2,5-diyne in the presence of cuprous chloride to form 1,1-diethoxyheptadeca - 2,5,8,11 - tetrayne, this was hydrogenated over Lindlar's catalyst to 1,1-diethoxyheptadeca-2,5,8,11-tetraene.  In Example 5, deca-1,4-diyne as its Grignard derivative was reacted with 1-bromo-3-methylbutene-2 in the presence of cuprous cyanide to give 2-methyltetradeca-5,8-diyne-2-ene, which was treated with perbenzoic acid and the epoxy compound so formed was decomposed to give 2 - methyltetradeca - 5,8 - diyne - 2,3 - diol, which was then hydrogenated over a Lindlar's catalyst to give 2-methyltetradeca-5,8-diene-2,3-diol.